Hand tool



- May 6 1924.

F. DUC HARME 149z680 HAND TooL Filed Sept. 1, 1922 avwentoz Franc/s Due/mime- 351 151141 Gamma;

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Patented ay 6, 1924.

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FRANCIS DUCHARME, F SHELBURNE FALLS, I MASSACHUSETTS, ASSIGNOR TO GOODELL-PRATT COMPANY, OF GREENFIELD, MASSACHUSETTS, A CORPORA- TION OF MASSACHUSETTS.

HAND TOOL.

Application filed. September 1, 1922. Serial No. 585,610.

To all whom it may concern:

Be it known that I, FRANCIS DUGHARME, a citizen of the United States of America, residing at Shelburne Falls, county of Franklin, and State of Massachusetts, have invented new and useful Improvements in Hand Tools, of which the following is a specification.

This invention relates to hand tools, such for instance as screw drivers, in which a metal shank is secured to a handle of wood or other suitable material and firmly held in position.

The principal object of the present invention is to provide a tool in which the shank is firmly secured in position in the handle, both against pulling out, and against turning, the construction being such that the handle cannot come ofl' unless it is destroyed.

provide a construction in which the force of a hammer or other instrument may be transmitted directly through the shank from the upper end of the tool to the working end thereof.

In the drawings accompanying and forming part of this specification, in which I have illustrated a preferred embodiment of my invention;

Figure 1 illustrates, partly in central longitudinal section, a screw driver made in accordance with the present invention;

Figure 2 shows the difierent parts of the tool in partly assembled positions;

Figure 3 is an enlarged view of the upper end of the shank with the ball in place;

Figure 4 is a transverse section taken on the line 44: of Fig. 1, looking in the direction of the arrows; and

Figure 5 is a transverse section taken on the line 5-5 of Fig. 2 looking in the direction of the arrows.

Similar characters of reference indicate corresponding parts throughout all figures of the drawings.

In these drawings, 1 designates a rod or shank, preferably of metal, and of circular section for the greater part of the length thereof, the upper portion 1 being of noncircular, preferably rectangular, cross section. The rod is flattened at the lower end thereof to form the blade portion or point 2 A further object of the invention is to of a screw driver or otherwise shaped to form the tool desired. The handle 3 has an axial bore 13 through the entire length thereof, said bore being smaller in diameter at the upper end for a distance corresponding approximately to the length of the rectangular portion 1 of the shank, so that when the shank is driven into the handle, the rectangular portion will be forced into the wall of the bore of said handle and tend to firmly hold the shank in the handle.

The upper end of the shank 1 has a conical recess 5 provided therein,thereby forming four prongs 6. The upper end of the handle 3 is countersunk at 14: for the reception of a metal cap 7, which cap has a central opening or recess 8 formed therein on the lower side of the same to a depth approximately one half the thickness of the cap. The bottom 9 of this opening or recess 8 also has formed therein a cup-shaped recess 10.

In assembling the tool, the shank 1 is forced into the handle 3, projecting upward into the countersunk portion 14, and a ball 11, such as used for ball bearings, or other object of a material harder than the shank, inserted in the recess 5 in said shank. The cap 7 is then driven over the upper end of the shank 1. By reason of the fact that the ball 11 is of harder metal than the metal of the shank, it will be forced downwardly into the conical recess 5 and thus force the edges 12 of the shank into the cylindrical opening 8 of the cap by reason of the wedging and expanding action of the ball against the side walls" of the recess 5. The recess 10 is provided for the purpose of holding the ball in its proper position in the center of the recess 5 and cap 7 so that an equal pressure will be exerted on all portions ,of the wall of the recess 5 when the cap is driven over the end of the shank.

Having now described my invention, I claim and desire to secure by Letters Patent:

A hand tool comprising a handle having an axial bore therethrough, a shank passing through said bore having a recess at the upper end thereof, the upper portion of said shank bein rectangular, said bore being smaller in diameter than the diagonal of the rectangular portion of the shank, so

that the edges of the rectangular portion Will be forced into the Wall of the bore, a cap having a cylindrical opening adapted to be driven over the upper end of the shank,

a ball disposed in the recess of the shank and serving as a means whereby the edges of theshank will be wedged against the Wall of the cylindrical opening of the cap and as a means whereby the force of a blow on the cap may be transferred therefrom to 10 the shaft.

In testimony whereof I have signed my name to this specification.

FRANCIS DUCHARME. 

